Problem: $ { \left[\begin{array}{r}{2} \\ {-1} \\ {-1}\end{array}\right]-\left[\begin{array}{r}{0} \\ {0} \\ {3}\end{array}\right] = {?} } $
Solution: To find the difference of two matrices, subtract the corresponding items between each matrix. ${\left[\begin{array}{r}{2}-{0} \\ {-1}-{0} \\ {-1}-{3}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{r}{2} \\ {-1} \\ {-4}\end{array}\right]}$